Throw the oats or walnuts into a food processor until they become like rough flour. Add the rest of the ingredients to this and process until it all begins to stick together. Put a piece of parchment on a baking pan. Scoop on your cookie dough, then place another piece of parchment paper on top of that. Roll the cookie dough out between the two pieces of parchment (no mess!) then cut out your cookies. Use the extra dough to roll into balls. Refrigerate all this until the cookies can hold their shape (a couple hours).

To make the ice cream:

Blend the bananas until they turn into soft serve ice cream. (The texture will change suddenly.) Sandwich the ice cream between your cookies and enjoy! Makes approximately 4-6 sandwiches.

Notes: you can use any kind of nut butter you like. You can make the ice cream in a food processor. You can add a pinch of salt to the cookies, and vanilla to the ice cream. You can really do whatever you want.